Electronic structure, global reactivity descriptors and nonlinear optical properties of glycine interacted with ZnO, MgO and CaO for bacterial detection.

Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6-31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT). The Coulomb-attenuating approach (CAM-B3LYP) was utilized to obtain theoretical electronic absorption spectra with the 6-31G(d, p) basis set to be more accurate than alternative quantum chemical calculation approaches, showing good agreement with the experimental data. The TDM and FMO investigation showed that glycine/CaO model has the highest TDM (10.129Debye) and lowest band gap (1.643 eV). The DFT computed IR and the experimental FTIR are consistent. The calculated UV-vis spectra showed a red shift with an increase in polarity following an increase in the absorption wavelength due to the interaction with ZnO, MgO, and CaO. Among the five solvents of water, methanol, ethanol, DMSO and acetone, the water and DMSO enhances the UV-Vis absorption. Glycine/CaO model showed high linear polarizability (14.629 × 10